Acute and chronic lung diseases remain the most life threatening causes of death and hospitalization in the pediatric population. Cystic fibrosis (CF), pulmonary hypertension and pulmonary fibrosis have been observed to be the most frequent causes of lung failure in pediatric patients. Mechanical ventilation (MV) and extracorporeal membrane oxygenation (ECMO) have been used to bridge sick kids to transplant. These procedures can lead to poor post-transplant outcomes by their very restrictive nature on mobility. This project will develop a compact respiratory assist device for pediatric patients, the Pittsburgh Pediatric Ambulatory Lung (P-PAL) to replace ECMO as a bridge to transplant or recovery in kids with acute and chronic lung failure. The P-PAL is a wearable and fully integrated blood pump and gas exchange module that will be designed for implantation of inflow cannula and outflow cannula/grafts in the right atrium and pulmonary artery, respectively. The P-PAL will be designed for longer-term respiratory support (1-3 months before cartridge change-out) at 70- 90% of normal metabolic oxygenation requirements, while pumping blood from 1 to 2.5 Liters/min. The specific aims of project are 1) To modify the design and operational parameters of the P-PAL to meet requirements for blood pumping, gas exchange, priming volume, and form factor, 2) To build P-PAL prototypes along the design development pathway for bench characterization studies of pumping performance, gas exchange, and hemolysis, 3) To improve the hemocompatibility of the P-PAL by exploiting novel polymeric zwitterionic coatings that we have already begun to develop for our adult wearable assist lung, and 4) To perform acute and chronic studies in healthy lambs to demonstrate the in-vivo performance and hemocompatibility of the PAAL device and to study its interaction with the cardiopulmonary system.